Method for removing solidified ink or varnish using adhesive strips

ABSTRACT

A method for removing solidified ink or varnish from a surface includes applying a cleaning agent to the ink on the surface. The cleaning agent applied to the ink on the surface is substantially solvent-free and water-based and reduces adhesion between the ink and the surface without dissolving the ink. An adhesive side or face of a single-sided or single face adhesive element is applied to the surface. As the adhesive element is removed from the surface, the ink that has been treated with the cleaning agent but is undissolved adheres to the adhesive element and is thus removed from the surface together with the adhesive element without splitting.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority, under 35 U.S.C. §119, of GermanPatent Application DE 10 2014 004 363.0, filed Mar. 27, 2014; the priorapplication is herewith incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a method for removing solidified ink or varnishfrom a surface of an object in which a cleaning agent is applied to theink on the surface.

Known methods for removing layers of solidified ink or varnish rely onthe use of a solvent, generally subjecting the surface to stress. Inorder to effectively remove layers of ink, in most cases, the surface isadditionally subjected to rubbing or scrubbing. That may damage thesurface or result in undesired surface changes. Moreover, that processonly removes the layer of ink bit by bit. In addition, small bits of inkmay be created that in turn stick to the surface and need to be removedin a time-consuming second cleaning step. A process of removing layersof ink of that kind has turned out to be difficult, in particular forstrongly or greatly curved surfaces.

European Patent EP 1 875 490 B1, corresponding to U.S. Pat. No.8,752,228, discloses a device for cleaning circuit substrates. In oneembodiment of that invention, the circuit substrate is passed through agap between two rollers, each of which presses a cleaning web formed ofa carrier web and a cleaning tissue onto the surface of the circuitsubstrate. Initially, a cleaning liquid is applied either to the surfaceof the circuit substrate or to the cleaning tissue. The rollers guidethe cleaning tissue over the surface of the circuit substrate and thecleaning tissue removes contamination in the form of foreign particlesfrom the surface, absorbs them, and carries them away. In a furtherembodiment, the cleaning tissue carries an adhesive material. Theadhesive material and the material of the carrier web are selected toensure that adhesion between the carrier web and the adhesive materialis greater than adhesion between the adhesive material and the surfaceof the circuit substrate. During the cleaning process, there is norelative movement between the circuit substrate and the cleaning web.The rollers successively press a new section of the cleaning web ontoparts of the surface of the circuit substrate until the entire surfacehas been treated. In that process, the foreign particles stick to theadhesive surface of the cleaning web.

Japanese Patent Application JP 2001 353 856 A discloses an adhesivesheet for removing solvent-containing substances from surfaces. Theadhesive sheet is formed of a base material and an adhesive layer, whichis applied to at least one surface of the base material. The adhesivesheet is immersed in the solvent contained in the substance to beremoved for three minutes and the adhesive layer absorbs at least 20g/m² of the solvent.

SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide a method forremoving solidified ink or varnish using adhesive strips, whichovercomes the hereinafore-mentioned disadvantages of theheretofore-known methods of this general type and which represents animprovement for removing solidified ink from surfaces, in particularfrom curved surfaces.

With the foregoing and other objects in view there is provided, inaccordance with the invention, a method for removing solidified ink orvarnish from a surface of an object. The method comprises applying acleaning agent to the ink on the surface, the cleaning agent applied tothe ink on the surface being substantially solvent-free, water-based andreducing adhesion of the ink to the surface without dissolving the ink,applying an adhesive side of a one-sided adhesive element to thesurface, and removing the adhesive element from the surface togetherwith the ink having been treated with the cleaning agent but beingsubstantially undissolved and adhering to the adhesive element withoutsplitting.

On one hand, the method of the invention for removing solidified ink orvarnish is suitable for cleaning printed objects that have been providedwith ink or varnish, for instance auto body parts. On the other hand,the method may be applied specifically to remove defined areas of alayer of ink irrespective of their shape and size. In the context of thepresent invention, for reasons of linguistic simplicity, ink and varnishwill be commonly referred to as “ink,” i.e. the term ink is understoodto include varnish.

In order to remove ink, a cloth is used to apply a thin film of asubstantially solvent-free, water-based cleaning agent to the region orpart of a solidified layer of ink that is to be removed. This cleaningagent permeates the layer of ink to undermine the layer of ink, reducingadhesion of the layer of ink to the surface without dissolving the ink.A preferred cleaning agent is a cleaning agent manufactured by Bubblesand Beyond GmbH, Leipzig (DE), for example a product referred to asIF07. After a residence time of up to three minutes, an adhesive film isapplied to and preferentially pressed onto the treated part of the layerof ink. This adhesive film is preferentially removed immediately afterapplication. Substantially the entire treated layer of ink adheres tothe adhesive film. The surface part that has been treated in this way isfreed from the layer of ink without any residues. The ink layer has notbeen split. If the ink had been partially dissolved, splitting of thelayer of ink would be expected to occur, resulting in an incompleteremoval in contrast to the present invention.

The ink may previously have been printed onto the surface of an objectin an inkjet printing process. The surface may be a curved surface andthe print head may be moved by a robot or the like as described, forexample, in German Patent Application DE 10 2012 006 371 A1,corresponding to U.S. Patent Application Publication No. 2015/0042716.

In accordance with a first preferred further development of theinvention, a provision is made for the solvent-free cleaning agentinitially to be applied to an impermeable flexible carrier medium suchas a plastic foil. Subsequently, the carrier medium carrying thecleaning agent is applied to a region to be treated of a layer of ink ona surface. After a residence time of approximately three minutes, thecarrier medium is removed. Then the process continues as describedabove. A particular advantage of this process is that the shape of thearea to be removed may be precisely defined and the amount of cleaningagent is adapted to the area to be removed in an optimum way.

In accordance with a further embodiment of the invention, a provision ismade for the cleaning agent to be applied directly to the adhesive filmand to be applied to the surface or area to be treated together with theadhesive film. This accelerates the cleaning process because theapplication of the cleaning agent to a first foil and the applicationand removal of a first foil are dispensed with.

In accordance with a further embodiment of the invention, a provision ismade for the cleaning agent to be provided in capsules disposed on theadhesive side of the adhesive film. When the adhesive film is applied tothe layer of ink to be treated, the capsules open due to the pressingforce to release the cleaning agent, which then disperses between theadhesive element and the layer of ink. If the cleaning agent is applieddirectly on the foil, it is in danger of running off, causing loss ofcleaning agent and increasing the cleaning effort required to clean thework environment. Providing cleaning agent in capsules additionallyimproves storage stability and prolongs shelf life. The advantageous useof capsules prevents the cleaning agent from running off and allowsaccurate metering of the applied amount of cleaning agent.

In accordance with an advantageous further embodiment of the invention,a provision is made for the cleaning agent to be applied to the surfaceusing an inkjet head. This allows the accuracy of the application ontothe area to be treated and the metering of the applied amount ofcleaning agent to be even further optimized. Moreover, the process maybe exactly repeated due to the use of an inkjet. Alternatively, thecleaning agent may be applied by a spray head, for instance by aso-called airbrush device.

In accordance with a further advantageous embodiment, a provision ismade for the cleaning agent to be applied only to edge regions of thearea to be removed of the layer of ink. In the edge regions, theundermining of the layer of ink is most effective. This allows theamount of cleaning agent being used to be reduced.

In accordance with a further embodiment, a provision is made for excessapplied cleaning agent to be removed from the layer of ink using aliquid-absorbent cloth. This improves adhesion between the layer of inkto be removed and the adhesive film because there is no undesired layerof cleaning agent between the adhesive layer and the layer of ink.

In accordance with an advantageous further embodiment, after the excesscleaning agent has been removed from the layer of ink using aliquid-absorbent cloth, the surface area that has been treated withcleaning agent is rinsed with water and subsequently dried to furtheroptimize adhesion between the adhesive film and the layer of ink becausethe rinsing and subsequent drying removes all adhesion-reducing liquidresidues on the layer of ink.

In accordance with an advantageous further embodiment of the invention,a provision is made for the solvent-free cleaning agent to be a gel.

In a further embodiment, the layer of ink to be removed is a layer ofink that has been cured using UV light and had preferably been appliedin an inkjet printing process.

In accordance with an advantageous further embodiment, the layer of inkto be removed is a thermally cured layer of ink, which may also havebeen created in an inkjet process. Alternatively, an oxidatively-curingink may be used.

Other features which are considered as characteristic for the inventionare set forth in the appended claims.

Although the invention is illustrated and described herein as embodiedin a method for removing solidified ink or varnish using adhesivestrips, it is nevertheless not intended to be limited to the detailsshown, since various modifications and structural changes may be madetherein without departing from the spirit of the invention and withinthe scope and range of equivalents of the claims.

The construction and method of operation of the invention, however,together with additional objects and advantages thereof will be bestunderstood from the following description of specific embodiments whenread in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a diagrammatic, plan view of a surface covered by a UV-curedlayer of ink;

FIG. 2 is a plan view of the same surface having areas to which acleaning agent has been applied;

FIG. 3 is a plan view of the same surface with an adhesive film appliedto the areas that have been treated with cleaning agent; and

FIG. 4 is a plan view of the same surface after the adhesive film hasbeen removed.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the figures of the drawings in detail and first,particularly, to FIG. 1 thereof, there is seen a surface 1 covered by aUV-cured layer of ink 2. An inkjet head 5 applies a solvent-freecleaning agent 3 to a part of the surface 1. The cleaning agent 3reduces adhesion of the UV-cured layer of ink 2 to the surface 1 withoutdissolving the layer of ink 2. FIG. 2 illustrates the surface 1 with theapplied cleaning agent 3. After a residence time of approximately threeminutes, excess cleaning agent 3 is removed by using a liquid-absorbentcloth 6. The surface part that has been treated with cleaning agent 3 isrinsed with water 7 and dried, for instance by using a cloth 8 or ablower. After the drying step, an adhesive film 4 is applied to thesurface part that has been treated with cleaning agent 3 as shown inFIG. 3. This adhesive film 4 is removed immediately after application tothe surface 1. The ink 2 that has been treated with the cleaning agent 3adheres to the adhesive film 4 and is removed from the surface 1together with the adhesive film 4. FIG. 4 illustrates the surface 1 oran area 1 a thereof that has been partially freed of UV-cured ink 2 inaccordance with the present method.

1. A method for removing solidified ink or varnish from a surface of anobject, the method comprising the following steps: applying a cleaningagent to the ink on the surface, the cleaning agent applied to the inkon the surface being substantially solvent-free, water-based andreducing adhesion of the ink to the surface without dissolving the ink;applying an adhesive side of a one-sided adhesive element to thesurface; and removing the adhesive element from the surface togetherwith the ink having been treated with the cleaning agent but beingsubstantially undissolved and adhering to the adhesive element withoutsplitting.
 2. The method according to claim 1, which further comprises:initially applying the cleaning agent to an impermeable flexible carriermedium; applying the carrier medium with the cleaning agent to thesurface to be treated; and removing the carrier medium from the surface,leaving a thin film of the cleaning agent on the surface.
 3. The methodaccording to claim 1, which further comprises applying the cleaningagent directly to the adhesive element and applying the cleaning agentto the surface together with the adhesive element.
 4. The methodaccording to claim 1, which further comprises: providing the cleaningagent in capsules disposed on the adhesive element; opening the capsulesas the adhesive element is pressed onto the surface; and releasing anddispersing the cleaning agent between the adhesive element and thesurface.
 5. The method according to claim 1, which further comprisesapplying the cleaning agent to the surface using an inkjet head.
 6. Themethod according to claim 1, which further comprises applying thecleaning agent only to edge regions of an area of the surface coveredwith solidified ink.
 7. The method according to claim 1, which furthercomprises removing excess cleaning agent using a liquid-absorbent cloth.8. The method according to claim 7, which further comprises rinsing withwater and subsequently drying a part of the surface having been treatedwith the cleaning agent.
 9. The method according to claim 1, wherein thecleaning agent is a gel.
 10. The method according to claim 1, whereinthe ink to be removed is a layer of ink having been cured by UV light.11. The method according to claim 1, wherein the ink to be removed is alayer of ink having been cured thermally or oxidatively.